Open-hearth furnace.



UNITED-STATES `FArFnrr oFFioF.

NnLsoN THOMAS AND ANsoN W. ALLEN, oF BIRMINGHAM, ALABAMA.

, OPEN-HEARTH FURNACE.

Specification of Letters Patent.

Patented Feb. .27, 1917.

original application filed- '.raiy lo, 1914, serial No. 850,131.'Diiified and 'this appiication filed necinher 16',

' 1915. serial No. 67,151.

To all whom t may concern Be it known that we, NELsoN ANsoN lV. ALLEN,citizens of the United States, and residing at Birininghain,in the'county of Jefferson, State of Alabama, have invented certain new anduseful Improvements in Open-Hearth Furnaces, of-Which a furnace adaptedfor the burning of byroduct wasl therein.

This application is a division'v of my application, Serial No. 850,131,filed July 10,

1914, and which was patented- Feb. 15, 1916,- Y

It has not heretofore been found possible or practicable to employby-product gas in open hearth furnaces.A By the term byproduct gas werefer to gas evolved in the making ofv coke `from coal 1n retort ovens.The reasons for the lmpracticabillty of burnin-O' this gas may possiblyrelate more to the lack of adequate facilities in the construction ofthe open lieartll furnaces than to the character of the gas itself.. We`have found, however, that such gas may be burned 1nopen hearth furnacesto advantage and Withoutmaterially altering the port construction of thefurnaces.

In the utilization of by-product gas it has been found essential tohighly heatthe same in order to secure complete and speedy combustion.We accomplish this result in the present instance by constructing thefurnace with a main and auxiliary air flue, the gas A being supplied tothe auxiliary flue by means of thegas, that is combustion to the extent,

of a gas pipe, short of the mouth of the auxiliary flue, thus leaving aspace within which primary com#l bustion may take place. By suchmechanism we are enabled to cause partial combustion permitted. by thelimited volumeof air in the auxiliary flue, thus highly heating theremainder of the gas, which is ejected into the larger space and mixedwith the required volume of air to cause complete and speedy combustion.

It will be noted that the open hearth furi nace is not lgreatly 'changedfrom the design heretofore commonlyV in use, except by the l. fg 1iti011 thereto of the gas burning means ""and the changing of thefunction ofone of THOMAS and which gas pipe terminates that'- of supplying gas tothat of supplying air.

The invention will be more readily understood by reference to theaccompanying drawings, wherein- Figure l is al longitudinal verticalsection through an end of a tilting .open hearth lfurnace, to which ourinvention has been apl plied;

Fig. 2 is a transverse section on the line Elf-2 of Fig. l, andv Fig. 3is a section' on the line 3 3- of Fig. 1;.'

Referring more particularly to the drawings, it wil be seen that weprovide an open hearth furnace 10 which, in the present instance,isofthe tilting type. 'The end construction consists in an end-wall 11,'alower wall 1 2 and an upper wall 18, wit-hin whichv walls is provided amain ail-V flue 14 and an auxiliary air flue 15. The main air fiile isdivided as shown in Fig.l 2, the two l,portions uniting at apointabovethe division arch 16, the auxiliary flue extending underneath thearch-16. .In View of the fact-that when the furnace is reversed the heataround the arch 16 is very great, we Vprefer to provide within the archthe longitudinally extending .Water-cooled. boxes!A 17, laid, as shown`in Fig. 2, with their sides in engagement, thus forming aself-supper,ting arch.. 7Water is supplied/tol these 'boxes by -meanslofthe.-

plpe 18.

Extending intothe ai'ixiliary'iue "15 is a gaspipe' 19, surrounded by 'afurther pipe 20, between which pipes water'may be cir# Culated toprevent overheating. Gas is supplied to the pipe l19 by the main 21,having a vvalve 22 therein. 'by means of which -the supply iscontrolled. Located centrally within the gas pipe- 19 is a high pressureair pipe 23, the end of which is located near the mouth 4of the gaspipe. Ye prefer to maintain the pipe Q3 centrally within the gas pipe`by means ofv abend '2l in the ail-pipe. as shown. l f It will be notedthat the gas pipe is termi'- nated short of the nose of the arch 1G,thus leaving a space which acts as a coinbustion chamber (if-limitedvolume. the walls ofv which chamber are constricted near the mouth ofthe chamber, as best shown in Flgs.

, 1 and 3. tapering the chamber and inaking the mouth. thereof ofreduced cross-sec-v initial combustion takes place, that -is suchcombustion as is possible. in view of the limited volume of 'oxygen'present. This eolll'ibustion, however, highly heats the .un-

consumed gas and this is delivered into the main combustion space at theconlux of-'the t\1v o ues, where complete combustion takes p ace.k

The direction ofthe flame is controlled to a certain extent by means ofthe high pressure air pipe 23. rlhis, taken in connection with thetapering of the walls of the chamber 25, enables us to utilize a veryhigh degree of heat Without directing the flame against the roof or sidewalls of the open hearth furnace.

l lt will be understood, of course, that the air supply through theflues 14, 15 may or may not be regenerated, as desired, preferably,however, it will be highly heated by passing through regenerators, as iscustomary in the operation' of such furnaces.

i We claim: f

1. Ilnan open hearth furnace, the combination of Walls providing aplurality of vertical Hueswhich are turned at an acute angle in order toextend in a downward direction toward the hearth of the furnace and apipe projected through the furnace endwall across one of saidverticallues and extending in a line substantially parallel to thedownwardly extending portion of said flues, said pipe terminating shortof the outlet from the flue in which it is mounted, substantially asdescribed.

2. In an open hearth furnace, the combination of furnace walls providinga plurality, of uptake ues, said flues being turned at their upper endsto' projectv downwardly toward the furnace hearth, said lues .having acommon inlet port to the furnace, and a pipe projected through thefurnace end wall across an intermediate vertical flue and in line withthe downwardly extending portion of said flue, said pipe being arrangedto deliver fluid in line with the travel of the Huid 1within the -iueand thereby avoid whirls and cross currents, substantially as described.

In witness whereof we have hereunto set our names 1n the presence of twosubscrlh-

